$\text{a)}\left|-3\right|\cdot 70=3\cdot 70=210$  

$\left|-8\right|\cdot \left|-6\right|=8\cdot 6=48$  

---

$\text{b)}\left|-60\right|:\left|-12\right|=60:12=5$  

$\left|-110\right|:\left|-10\right|=110:10=11$  

---

$\text{c)}\left|-4\right|+\left|-6\right|=4+6=10$  

$\left|-20\right|-\left|-30\right|=20-30=-10$